Bagging of dusty particulate solids



Sept. 22, 1964 c. x 3,149,649

BAGGING OF DUSTY PARTICULATEI SOLIDS Filed June 24, 1960 TO VAC- SYSTEM BAG SEALER INVENTOR. M.C. HIX

F/G. By 4 A TTORNEYS United States Patent 3,149,649 BAG'GING 0F DUSTY PAR'E'IQULATE SOLIDS Marvin C. Hix, Dumas, Tern, assignor to Phillips Petroleum Company, a corporation of Delaware Filed June 24, 1960, Ser. No. 38,597 2 Claims. (Cl. 141-93) This invention relates to a process and apparatus for bagging dusty, particulate solids and for adhesively sealing the bags.

It is common practice to utilize adhesive pressure sealing tape to seal paper bags and bags fabricated from plastic sheet or film or to heat the plastic to adhesively seal the mouth of the bag. When solid particulate materials are sacked or bagged, dust from the materials contaminates the inside as Well as the outside of the bag at its top or mouth to such an extent that it is dimcult to seal the bag adhesively. This is particularly true when sacking carbon black, clay-coated ammonium nitrate, ammo nium sulfate, particulate plastics (polyethylene) and similar materials. It has been found necessary when filling plastic bags with such materials to wipe the top portion of the bag free of dust in order to permit it to be elicctively sealed by heat sealing means. The same is true when sealing the bag with adhesive pressure tape. The individual wiping or cleaning step is undesirable in that it requires man-hours to perform the operation and unneces sary expense if it can be avoided. In view of the fact that plastic bags and plastic coated paper bags are coming into greater use for packaging and shipping the abovementioned materials, due to the greater strength of the bags and lower loss of materials in shipping, the elimination of the cleaning or wiping step in bag sealing is of substantial significance.

Accordingly, it is an object of the invention to provide an improved process and apparatus for bagging dusty particulate solids which maintains the open mouth of the bag relatively free of dust to facilitate adhesive sealing of the open mouth of the bag. Another object is to provide improved adhesive sealing of plastic bags after filling same with dusty, particulate solids. A further object is to provide an improved process and apparatus for filling plastic bags, such as polyethylene bags, with dusty, particulate solids for adhesive sealing. Other objects of the invention will become apparent upon consideration of the accompanying disclosure.

Particulate solids are conventionally bagged by extending a filling spout into the mouth of a bag to be filled and dumping a measured amount of the solids into the filling spout from which they gravitate into the bag. Unless precautions are taken, dust from the particulate solids deposits on the inside and outside of the mouth of the bag to interfere with adhesive seal of the bag. In order to provide a strong adhesive seal on the mouth of the bag, it is essential to wipe the surface to be sealed to free the same of dust particles or to prevent the depositing of dust thereon.

A broad aspect of the invention comprises sucking air into the bag thru space between the mouth of the bag and the filling spout and up thru the filling spout to an exhaust means connected therewith. This in reality amounts to maintaining a lower gas pressure within the bag during filling than ambient gas pressure, which causes gas (air) to pass into the bag thru the annulus between the bag and the filling spout and up thru the filling spout to the evacuation or exhaust line. By this means and method, the flow of dust from the interior of the bag is restricted strictly to the inside of the filling spout and no dust is allowed to contact the inside of the mouth of the bag surrounding the spout.

In some applications, the filling spout is extended well into the bag and is progressively withdrawn as the bag 3,149,649 Patented Sept. v22?, 1 964 is filled; or the bag is lowered from the spout as the filling proceeds. In other applications the filling spout is extended into the bag a short distance, such as 2 to 4 inches or more, and the mouth of the bag is clamped around the filling spout. In the latter instance, it is extremely diflicult to provide a complete seal between the inside of the mouth of the bag and the spout. Hence, the application of suction within the filling spout and bag pulls air thru any existing passageway between the mouth of the bag and the spout to prevent passage of dust therethru and contamination of the mouth of the bag with dust.

A more complete understanding of the invention may be had by reference to the accompanying schematic drawing of which FIGURE 1 is an elevation in partial section of bagging apparatus arranged in accordance with the invention; and FIGURE 2 is a plan view in partial section of clamping means around the filling spout of FIGURE 1.

Referring to FIGURE 1, numeral 10 designates a conventional, commercially available preweighing scale supplied with material from above by means not shown. The case 12 of this scale is reasonably or substantially gas tight. A fill box 14 receives material until the predetermined weight of the material has been deposited in the box, at which time it is ready for dumping. The chute 16 receives the dumped material which gravitates into filling spout 13 and into bag 20. Bag 20 is clamped to the lower end of spout 18 by means of clamping device 22 which is operated by means of air piston 24.

An exhaust conduit or line 26 connects with the upper side of chute 16 and is provided with an exhaust means, or other evacuation device. This exhaust line could also enter the system at other points along the enclosed route of the material. A butterfly valve 28 having operating arm 30 is positioned in conduit 26 to control the application of vacuum and flow of gas thru this conduit. Arm 30 is connected with the rod 32 of air piston 34.

Dumping of the weighed amount of solids in box 14 is controlled by air piston 36 connected by mechanical linkage 38 with conventional tripping mechanism within preweighing device 16. After each dumping or tripping step, box 14 automatically returns to the fill position. Conveyor 40 receives bag 20 after filling and moves the same to bag sealer 42 which clamps the mouth of the bag shut and applies heat thereto so as to render the inside contacting surfaces of the bag sufiiciently adhesive and weld them together by adhesion. Bag sealing in this manner is conventional and requires no further disclosure.

It is also feasible to seal the filled bag by means of pressure adhesive tape applied across the top of the closed lips of the bag and extending down onto the outside of the bag on each side of the top. This is also a conventional procedure and requires no further explanation.

In practice it was found that maintaining evacuation thru conduit 26 at all times was impractical and rendered it difiicult to properly position plastic bag 20 on the delivery end of filling spout 18. The flow of air into the delivery end of the spout during bag positioning or clamping caused the plastic bag to be sucked into or against the spout and prevented proper clamping or positioning of the bag around the spout. In order to overcome this problem a control system was devised for operation of the device. Each of operating pistons 24, 34, and 36 is served by a common air line 44 which is connected with an air pressure supply line 46. A control valve 48 in supply line 46 is operated by a foot pedal 50 and this is positioned so that the operator can depress pedal 50 after positioning bag 20 around the lower end of the delivery spout in clamping position so as to open valve 48. By depressing pedal 50, air is supplied to each of the operating pistons to simultaneously clamp bag 50 by means of clamp 22, dump the load from box 14, and open butterfly valve 28 in conduit 26. In this manner, bag 20 is clamped in position and the vacuum applied thru line 26 becomes effective at the delivery end of the filling spout before or at least by the time dust appears in the bag area. As the bag is filled, the exhaust system pulls or sucks air into the bag and the filling spout from any passageway existing between the bag and the spout and also evacuates displaced air from the inside of the bag as the material is bagged.

In operation, when pedal 50 is released, the pressure in lines 44 is also released to allow the pistons in air cylinders 24, 34, and 36 to return to their normal positions, thereby releasing clamp 22, closing valve 28, and positioning the piston of air cylinder 36 for the succeeding tripping or dumping operation.

While air-operated controls are shown for the clam vacuum line valve and tripping device, these may be electrically operated and controlled or they may be manually operated simultaneously or in closely timed sequence. When manually operated, bag 20 should be clamped in place first, followed by opening of valve 28 and then dumping of the material from box 14-.

In FIGURE 2, delivery spout 18 is shown in ovalshaped cross section. Clamp 22 is split at 54 so as to form two halves 56 and 58. Both halves are operated simultaneously by means of linkage 69 (FIGURE 1) which connects with piston rod 62 of the air cylinder 24. In this linkage 64 is a fixed fulcrum which allows rod 66 to oscillate and move section 56 of the clamp into and out of clamping position.

Other suitable clamping means may be utilized in lieu of that shown. It is also feasible to merely hold bag 20 in loose relation to filling spout 18.

Certain modifications oi the invention will become apparent to those skilled in the art and the illustrative details disclosed are not to be construed as imposing unnecessary limitations on the invention.

I claim:

1. Apparatus for loading dusty, particulate solids into bags adapted for adhesive sealing comprising in combina tion enclosed means for measuring a given quantity of said material and dumping same, includ ng a downwardly directed filling spout positioned to receive same; first operating means for effecting the dump; an exhaust line connected with the interior of said spout and provided with exhaust means; a valve in said exhaust line for closing same; second operating means for said valve; a clamp around the delivery end of said spout for holding the mouth of a bag around same for filling; third operating means for said clamp; and common actuating means for said first, second, and third operating means, whereby, upon actuation, the clamping of said bag, the opening of said valve, and said dumping are effected simultaneously and, upon release of said actuating means, said valve is closed and said clamp is released.

2. The apparatus of claim 1 wherein said first, second, and third operating means comprise compressed air operated pistons and said common actuating means comprises a valve in an air supply line feeding said pistons.

Reierenees ited in the file of this patent UNITED STATES PATENTS 2,003,337 Brady et al June 4, 1935 2,524,560 Cote Oct. 3, 1950 2,613,022 Peterson et al. Oct. 7, 1952 2,749,686 Lorenz et al June 12, 1956 2,757,894 Kindseth Aug. 7, 1956 2,815,046 McBean et al Dec. 3, 1957 2,922,443 Jones et al Ian. 26, 1960 FOREIGN PATENTS 492,560 France July 11, 1919 687,963 Great Britain Feb. 25, 1953 

1. APPARATUS FOR LOADING DUSTY, PARTICULATE SOLIDS INTO BAGS ADAPTED FOR ADHESIVE SEALING COMPRISING IN COMBINATION ENCLOSED MEANS FOR MEASURING A GIVEN QUANTITY OF SAID MATERIAL AND DUMPING SAME, INCLUDING A DOWNWARDLY DIRECTED FILLING SPOUT POSITIONED TO RECEIVE SAME; FIRST OPERATING MEANS FOR EFFECTING THE DUMP; AN EXHAUST LINE CONNECTED WITH THE INTERIOR OF SAID SPOUT AND PROVIDED WITH EXHAUST MEANS; A VALVE IN SAID EXHAUST LINE FOR CLOSING SAME; SECOND OPERATING MEANS FOR SAID VALVE; A CLAMP AROUND THE DELIVERY END OF SAID SPOUT FOR HOLDING THE MOUTH OF A BAG AROUND SAME FOR FILLING; THIRD OPERATING MEANS FOR SAID CLAMP; AND COMMON ACTUATING MEANS FOR SAID FIRST, SECOND, AND THIRD OPERATING MEANS, WHEREBY, UPON ACTUATION, THE CLAMPING OF SAID BAG, THE OPENING OF SAID VALVE, AND SAID DUMPING ARE EFFECTED SIMULTANEOUSLY AND, UPON RELEASE OF SAID ACTUATING MEANS, SAID VALVE IS CLOSED AND SAID CLAMP IS RELEASED. 